The present invention relates to a ratchet wrench and, more particularly, to an improved structure of ratchet wrench.
As shown in FIG. 1, a conventional ratchet wrench 1 is generally comprised of a wrench body 10, a ratchet wheel 20, a stop block 30, and a spring 40. The two ends of the spring 40 are inserted to a hole 11 of the wrench body 10 and a hole 31 of the stop block 30 respectively to force the stop block 30 into engagement with the ratchet wheel 20, enabling the ratchet wheel 20 to be rotated in the wrench body 10 in one direction only. The spring 40 is mass-produced by machine, having the determined length. However, because the processing of the hole 11 is disposed inside the wrench body 10, its processing is not easy. A special machine tool is needed to make the hole 11. When processing the hole 11, it is difficult to control the depth of the hole 11. Therefore, the fabrication of this structure of ratchet wrench may encounter the following problems.
1. If the depths of the holes 11 and 31 are excessively deep, the spring 40 cannot be properly compressed to support the stop block 30 positively in positive, and the ratchet wheel 20 may disengage from the stop block 30 when operating the ratchet wrench to turn a bolt or nut.
2. On the contrary, if the depths of the holes 11 and 31 are excessively short, the spring 40 will be maintained in a compressed condition before the stop block 30 receiving a pressure. In this case, the ratchet wrench loses its precision of torsion.
3. When making the holes 11 and 31, it requires much effort to carefully examine the depths of the holes 11 and 31, enabling the holes 11 and 31 to match the spring 40 perfectly.
The primary objective of the present invention is to provide a ratchet wrench, which has a stable torsion structure that achieves high performance. It is another object of the present invention to provide a ratchet wrench, which is easy to manufacture.
To achieve these objects of the present invention, the ratchet wrench comprises a wrench body having a receiving portion, an open chamber inside the receiving portion, and a blind hole in one sidewall of the open chamber, a ratchet wheel rotatably mounted in the receiving portion of the wrench body, the ratchet wheel having a toothed peripheral wall, a stop block mounted in the open chamber of the wrench body and adapted to engage the toothed peripheral wall of the ratchet wheel and to limit the direction of rotation of the ratchet wheel, and a spring member mounted in the open chamber to support the stop block and to force the stop block into engagement with the ratchet wheel. The diameter of the midsection of the spring member is greater than the diameter of the blind hole of the open chamber, and the diameter of one end of the spring member is smaller than the diameter of the blind hold such that said end can be inserted into the blind hole and the midsection is stopped by the sidewall of the open chamber.